[Bug libgcc/78252] New: C++ demangler crashes with infinite recursion

[P at draigBrady dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=78252

            Bug ID: 78252
           Summary: C++ demangler crashes with infinite recursion
           Product: gcc
           Version: unknown
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: libgcc
          Assignee: unassigned at gcc dot gnu.org
          Reporter: P at draigBrady dot com
  Target Milestone: ---

Created attachment 39991
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=39991&action=edit
problematic symbol

There is an infinite recursion in d_print_comp() in gcc-5 to gcc-6.2 at least.
Simple reproducer attached